/* kf_cos.c -- float version of k_cos.c
 * Conversion to float by Ian Lance Taylor, Cygnus Support, ian@cygnus.com.
 */

/*
 * ====================================================
 * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
 *
 * Developed at SunPro, a Sun Microsystems, Inc. business.
 * Permission to use, copy, modify, and distribute this
 * software is freely granted, provided that this notice
 * is preserved.
 * ====================================================
 */

#include "fdlibm.h"

static const float one = 1.0000000000e+00, /* 0x3f800000 */
    C1 = 4.1666667908e-02, /* 0x3d2aaaab */
    C2 = -1.3888889225e-03, /* 0xbab60b61 */
    C3 = 2.4801587642e-05, /* 0x37d00d01 */
    C4 = -2.7557314297e-07, /* 0xb493f27c */
    C5 = 2.0875723372e-09, /* 0x310f74f6 */
    C6 = -1.1359647598e-11; /* 0xad47d74e */

float
__kernel_cosf(float x, float y)
{
    float a, hz, z, r, qx;
    __int32_t ix;
    GET_FLOAT_WORD(ix, x);
    ix &= 0x7fffffff; /* ix = |x|'s high word*/
    if (ix < 0x32000000) /* if x < 2**27 */
        return one;
    z = x * x;
    r = z * (C1 + z * (C2 + z * (C3 + z * (C4 + z * (C5 + z * C6)))));
    if (ix < 0x3e99999a) /* if |x| < 0.3 */
        return one - ((float)0.5 * z - (z * r - x * y));
    else {
        if (ix > 0x3f480000) { /* x > 0.78125 */
            qx = (float)0.28125;
        } else {
            SET_FLOAT_WORD(qx, ix - 0x01000000); /* x/4 */
        }
        hz = (float)0.5 * z - qx;
        a = one - qx;
        return a - (hz - (z * r - x * y));
    }
}
